Driving-gear for electro-magnetically-propelled vehicles



(No Model.) 6 Sheets-Sheet 1.

W. L. STEVENS. DRIVING GEAR FOR ELEUTRO'MAGNETIGALLY PROPELLED VEHICLESv No. 394,734. Patented Dec. 18, 1888.

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0 e W. L. STEVENS. DRIVING GEAR FOR BLEGTRO MAGNETIGALLY PROPELLEDVEHICLES. No. 394,734. Patented Dec. 18; 1888.

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W. L. STEVENS.

6 Sheet sSheet 3.

DRIVING GEAR FOR ELEOTRO MAGNETIGALLY PROPBLLBD VEHICLES.

Patented Dec.- 18, 1888.

WITNEEGEE.

Ill 1/] STE AGNE (No Model.)

6 SheetsSheet 4. W. L, VENS. DRIVINQ GEAR FOR ELEUTRO'M TIGALLYPROPELLBD VEHICLES.

NO. 394,734 PatentedDeo. 18, 1888.

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6 Sheets-Sheet 5.

W. L. STEVENS.

Patented Dec 18, 1888.

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(No Model.)

DRIVING GEAR FOR ELECTED MAGNETIO'ALLY PROPELLED VEHICLES.

(No Model.) 6 SheetsSheet 6.

W. L. STEVENS. DRIVING GEAR FOR BLEUTROMAGN-ETIUALLY;PROPELLED VEHICLESNo. 394,734. Patented Dec. 18, 1888.

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UNITED STATES PATENT OFFICE.

\VILLIAM L. STEVENS, OF BOSTON, MASSACHUSETTS.

DRIVING-GEAR FOR ELECTRO-MAGNETlCALLY-PROPELLED VEHICLES.

SPECIFICATION forming part of Letters Patent No. 394,734, dated December18, 1888. Application filed March 5, 1888- Serial No. 266,132. (Nomodel.)

To all whom it may concern.-

3e it known that I, \VILLIAM L. STEVENS, a citizen of the United States,residing at Boston, in the county of Suffolk and State of Massachusetts,have invented certain new and useful Improvements in Driving- Gear forElectro Magnetically Propelled Vehicles, of which the following is aspecification, reference being had to the drawings accompanying andforming a part of the same.

This invention relates to apparatus or devices to be used on an y formof car, carriage, or other vehicle which is propelled by anelectromagnetic motor, or to be used in conjunction with anelectro-ma-gn etic or similar motor and any kind of driven mechanismwhere the same or similar conditions obtain.

The invention pertains more particularly to the intermediate mechanismby means of which the movement or rotation of the motor is transmittedor imparted to the driven mechanism.

In describing the invention I shall illustrate it herein as applied tothe special purpose of connecting an electro-magnetic motor carried by astreet or railway car to the axle or axles on which the wheels aresecured, and shall consider it mainly in connection with the specialneeds of such an application.

In carrying out my invention I have sought to meet as far as possiblethe practical requirements for the successful operation of street orrailway cars by means'of electric motors. In these respects my mainobjects are, first, to provide for the proper reduction of speed,whereby the motor may be run at a relatively high speed, as should bethe case to obtain the most economical results; second, to maintain aconnection between the driving and the driven mechanism which shall becapable of compensating for any difierences in the sizes or relativespeeds of the wheels of the two axles, whereby no power may be lost;third, to make the intermediate reducinggears more simple and in fewerparts and more compact, in order to economize in space and weight, and,fourth, to protect and inclose the gears and bearings, so as to excludedust and moisture.

The invention involves also other features of novelty which I shallpoint out more particularly hereinafter.

To accomplish the objects which I have thus generally enumerated, Iemploy a combination of devices which may be described in the followinggcmeral terms:

An electromagnetic motor is placed upon a car in any desired andconvenient manner and supplied with current from a battery carried bythe car or in other well-known ways, andsuitable devices are providedfor making, breaking, and reversing and controlling the said current. Onone or both of the car-axles is mounted a set or series ofreducing-gears, entirely inclosed in a cast-iron or similar casing,except the first member,which is a pulley or drum connected to themotor-pulley by a belt of suitable character, which-is carried throughsuitable openings in the case surrounding the pulley. The reducing-gearsare ,of special construction, consisting, essentially,

of a stationary interiorly-cogged wheel, between which and the sleeve towhich the drum or pulley is connected are intermediate gears or wheels,which, receiving motion from the sleeve and meshing with the interiorteeth or cogs, are caused to impart rotary motion to the axle. Variousmodifications of the gears are possible, and connections may be madefrom the motor to both axles, or from one axle to the other; but in suchcases the principle of the invention will be found similarly involved.The details of the construction of these parts, the manner in which theyfulfill their several functions, and the particular advantages whichthey secure will be more fully described by reference to the drawings.

Figure l is a view in side elevation of a motor secured 'under a car andmy improved connecting-gears combined therewith. Fig. 2 is a plan viewof the under side of a car with the invention applied thereto. Fig. 3 isa sectional detail on line 50 as of Fig. 4. of the reducing-gears. Fig.4: is a side elevation of the gears without the inclosing box or case.Fig. 5 is a section through the axles, showing in side elevation thedevices for imparting the rotation of the axle connected to the motor tothe other axle. Fig. 6 is a section on line y y of Fig. 5. Fig. 7 is asection through the axles, showing both axles geared to then'iotor. Fig.8 is a central vertical transverse section of motor-pulley of Fig. '7.

Fig. 9 is a longitudinal central section of a modified form of reducinganswers as a receptacle for containing oil.

gear. Fig. 10 is a section of the modification shown in Fig. Si, takenthrough the shaft between the pulley and reducing-gears 11 is a sectionon line .2 z of Fig. 8. Fig. 12 is an. end view of reducing-gears,forming a modification of that shown in Fig. 3.

A A represent the body of a car or similar conveyance; l; .I3,the axles,and l3 the wheels, which run on suitabletracks, A. l 'ndcr the car-bodyis suspended, or in any su itable manner securtal, an electro-magneticmotor, the current for driving which may be derived from a batterycarried by the car, or from a stationarygenoratorthrough the rails orother conductor.

On one of the axles, as l is a sleeve, l), loose or free to turn on theaxle, and to it is secured a pulley or drum, E. The pulley E Of themotor is geared to the pulley E by some form of flexible or :trictional.connection, such as a belt or a number of bands, F, composed of spiralsprings of steel, which. constitute a yielding connection asdistinguished from a positive gearing, and which may give. or slip underabnormal strain to prevent shocks and injury to the connections.

The drum E is of greater diameter than the pulley E, so that the speedof rotation of the pulley E and sleeve 1) is considerablyreduced. Theinn er end of sleeve D is formed or provid ed with gear-teeth (:lr,concentric with which is a ring, H, with interior teeth orcogs. The ringII is held against rotation by a link or bar, I, secured to the ring andthe car-bod y, respectively.

.l is a hub keyed to the axle B, and from it extend one orniore,')l.'O'f01'?ll')l three, arms J, each carrying at its extremity agear-wheel, K, meshing with the gear-teeth G and the in.- terior cogs orgears on ring ll. The number of the teeth G is smaller than that in eachof the wheels K, and there may be four or five times as many teeth in'I'I as in each wheel K; consequently one revolution of the arms .l andhub .l will require several revolutions of the sleeve 1).

L is a cast-metal head, havin a central hub, L, surrmnnling the axle lThe rinror ed gc of the head I. is secured by bolts I to the ring II,forming an oil-tight joint. Over the end of the hub l. is a circulardrip-cup, L", which is secured by a set-screw to ,the axle, and ascrew-plug, Z, inserted in a small opening, in the head to permit theintroduction of oil.

A head, M, with a central flanged opening, through which passes thesleeve D, is secured to the opposite edge of the ring II by the bolts.

I, thus completing a casing for the gears which In practice thisreceptacle is partially filled with oil, which occupies the lowerportion of the same and through which the wheels K pass. In this way thegears are protected from dust and moisture and thoroughlylulniicatied.Sn itable provision is also made for snm ilying the oil to theaxle-bearingsi?or instance, by the passages in. m,leading into anoil-space in. the hub L, and the passages m m leading to an oil-space inthe sleeve 1). A portion. of the oil. which is carried. up by the wheelsK in its descent iinds its way into these passages and lubricatcs theaxle.

A hood or cover, M, with an opening or openings to permitthc belt F topassthrmigh, incloscs the pulley E. A collar, M", with a groove, 71, isstaaircd to the axle l3, and the edge of the central opening of thecover M, entering said groove, forms a dust-joint.

The operation of the devices now (fleseribed is as follows: llpon thestarting of the motor its rotation is smoothly and steadilytransmitterfl to. the rcducing-gears by the yielding or flexible belt,which, it the strain is too great, gives or slips sulticiently to avoidany injury to the apparatus. It is desirable to have the drum or pulleyE much larger than that oil the motor to reduce speed; but itimpractical)le to reduce speed to an economical extent by means of onebelt, owing, mainly, to conditions of space. The advantages, therefore,of both belting and gearing are secured by making the pulley E the firstmember of a suitable train of gears. Tn the particular devices describedthe rotation of the pulley E and sleeve 1) in one direction imparts arotation about its axis of each of the wheels K in an oppositedirectionbut as the gear-ring l l, with which these wheels mesh, is stationary,the wheels are carried bodily around the sleeve and. impart motion tothe axle *3 in. the same direction. as the sleeve. The difference inspeed between the sleeve D and axle l; is thus reduced, so that the wearis comparatively slight.

\Vithout departure from the principle of this invention the constructionoi the reducing-gears may be considerably varied. Referring, forinstance, to Figs. 0 and It), in which the parts correspoinling to thosein the pre viously-dcscribed forms of ap mratus are dcsignaitalbysimilar letters of reference, E is a pulley with a long hub or sleeve,1), ti'lrning loosely upon the car-axle II. To the end of the sleeve isrigidly secured the eccentric t), which is also loose upon the axle andturns with the sleeve 1). A s1u1r-gear,-l, is mounted loosely upon theeccentric 0 in practically the same manner as the ec(':entric-strap ofan engine is mounted. The gear J" partakes ol. the motion of theGCCGl'llrlG, but is ircvented from rotating by the rod 0, bolted toit-and connected to a link, 0', pivoted to some stationary partof thecar-body, so as to be capable of a certain vertical. movement.

H is an internal or annular gear, kcycd or.

secured to the axle and concentric to the same by the disk or spindle.I. \Vith this gear meshes the spur-gear J. l 'nd er these conditionsthe rotation of the pulley E and sleeve T) will carry the gear .1 aroundwith the eccentric (I); but J being prevented from rotating, it willcause the gear 11 to revolve IIO ' V, fixed to the axle.

in the same direction as the pulley E, but at a slower speed, determinedby the difference between the number of teeth on J and II.

It is frequentlydesirable to impart by some form of gearing the movementof the motorshaft to both axles of the car. -This may be done by drivingboth axles from the motorshaft direct, or by communicating the motion ofthe driven axle to the other by suitable gearing between them.

\Vhen both forward and rear wheels are of exactly the same sizecircumferentially, this presents no great practical difficulties; butthe chilled wheels commonly employed on horse-cars are very liable todiffer slightly in size. To reduce them to a size by turning them is anexpensive proceeding; but to drive two axles having wheels of evenslightly-different size by one motor and by the ordinary mechanism isimpracticable and involves a great waste of power. Unde1-' eertaincircumstances I have found that nearly or quite double the power wasrequired to drive both axles that was needed for driving one. Myimprovements in this respect consist in the employment, with the motorand the axles, of intermediate motion-transmitting devices orconnections for imparting the motion of the motor-shaft directly orindirectly to both axles, one of which devices is adapted to compensatefor differences in the speed of rotation of the wheels of the respectiveaxles. I use the words n'lotion-transmittin g devices herein with theircommonly accepted and well-understood significance-that is" to say, theyare the intermediate belts, chains, or any other similarly-operatingmechanical elements, which impart the motion of one shaft to any other.

In illustration of thepriaciples involved, I have shown the belts andchains which in practice I haveadopted; but the invention is not limitedto these devices alone, and in referring hereinafter tomotion-transmitting pulleys and belts I wish to be understood asincluding all such other forms of motion-transmitting devices as arecommonly recognized as equivalent elements in similar combinations. Toavoid this in one way, I drive one axle, as before, by means of theextensible belt and reducing-gears. To this axle I secure asprocket-wheel, T, having, say, fortynine teeth. wheel, T, having, say,fifty teeth, and not fixed to the axle, but carrying a double-pivotedpawl, t, engaging with a 1Lt(3l16t-Wll66l, The pawl 25 is held up to itswork by a spring, 3, so constructed that the pawl may be shifted by handto engage with the tecthof ratchet V on either side of the center. Thepawl is shifted by hand when the direction of the car is changed. Thetwo sprocket wheels T T are connected by a sprocket-chain, \V.

Assuming the car-wheels to be all of the same diameter and the carmoving toward the left, or in the direction of the arrow, the

On the axle B is also a sprocket wheels on axle B will rotate at' thesame speed as those on axle B; but the sprocketwheel T would revolve alittle slower than the wheel T, or in the proportion of fortynine tofifty. At every revolution of the Wheels on axle B, therefore, one toothof the ratchet would pass-under the pawl, provided the driving-wheels onaxleB do not slip. The least slip of the latter, however, brings thepawl t up against one of the teeth of the wheel V, and power will thusbe transmitted from the axle B to axle B. All the wheels will thus bedriven whenever the wheels on axle B slip. On the other hand, assumingthe wheels of axle B to be smaller than the drivers and thesprocket-wheels of the same diameter, then during one revolution of thedrivers more than. one revolution of the other wheels would take place,and if the sprocketwlieel T were "fixed to shaft B the result would beto tighten the lower chain below the wheels and cause the rear wheels toslip. This obviously involves a great waste of power; but with thecompensating devices described the ratchetteeth slip under the pawl, andso prevent this tightening of the chain. So, generally, without theequalizing or compensating devices, any difference in the diameter ofthe drivers and driven wheels will result in a tightening of thesprocketchain, the side or portion of the chain tightened depending uponwhich set of wheels is larger, and also upon the direction of rotation.

To make the equalizing'device effective, it isnecessary, as will be seenfrom the above, that when no slip occurs there should be a difference inthe rate of movement of the driven axle and wheels and the sprocketwheelmounted on said axle, the normal tendency of the sprocket-wheel being tolag behind. This may evidently be secured by male *ing the two sprocketsof equal size and the driving-wheels larger than the others, so that incovering a given length of track the driven wheels will make a greater number of revolutions than the drivers and sprockets, or by making thesprocket-wheel on the driver-axle enough smaller than the other tocompensate for any differences in the sizes of the two sets of wheels.This latter plan I have found preferable, inasmuch as slight differencesin size are nearly always found in chilled car-wheels, and it is farmore convenient to secure the proper equalization by means entirelyindependent of the relative sizes of the wheels themselves. Thisdifference in the size of wheels, it will be understood, iscomparatively slight, and in practice I have found that a difference indiameter in favor of the drivers of one-fourth of an inch resulted in avery considerable saving of power. To properly understand the drawings,therefore, it should be assumed that either the drivers are larger,

also be understood that the object in using the chain or otherequivalent gearing between the two axles is not to impart positively atall times the movement of the drivers to the other wheels, but to driveall. the wheels when there is need of it, or, in other words, wheneverthe friction of the drivers is not sufficient to prevent slips andpropel the ear; and it will be observed of the devices described, aswell as those modifications hereinafter referred to, that no power isnecessarily transmitted to the wheels on axle ll' until a slip of thedrivers actually occurs; but such a slip is a natural one and does notrequire such an excess of power as that which occurs when the system isnot provided with the equalizing devices such as shown.

In practice the equalizing devices may be so proportioned, however, thatthe least slip in the drivers will drive the other wheels, or, in fact,to keep the equalizing devices driving at praeticall y all times.

In lieu of driving one pair of wheels by the other, both may be drivenby the motor-sha ft by independent belts; but in this case the sameobjections exist unless an equalizing device be employed. This Iaccomplish in the manner illustrated in Figs. 7, S, and 11.

In the other figures both axles, 1-3 B, are provided with thereducing-gears shown in Fig. 3, and the nmtor-pulley is connected tothem by the independent belts F F. The motor-pullev, however, iscomposed of two parts-one, E, loose upon the shaft, and another, E,secured to the shaft by a key, X, entering a keyway, Y, in the pulley ofsufficient width to permit aslight movement or play of the pulley on theshaft. Between the two pulleys, and Iixedto the shaft, is a collar, X,from which extends radially a light steel spring, Z, which passesbetween two pins or lugs, .2, set in a double pawl, R, pivoted to thepart E of the pulley and engaging with the ratchet-teeth Y on theinterior of the flange of pulley E. The pulleys E E or the gearing onthe axles are so constructed that the pulley E will drive the axle towhich it is connected at a very slightly slower-rate than the other axleis driven by pulley E. I would here state that, while not so shown inthe drawings, both pulleys should have the same number of grooves andcarry the same number of spring-belts. The operation of these devices isas follows: 'When the motor-shaft begins to turnto the right, as shownin Fig. 1l,the collar X and spring Z operate the pawl R, causing it toengage in. the teeth of the ratchet Y. At the same time the key Xencounters the end oi the keyway in pulley E, so that the ear is driventhrough the belts and gearing connected to pulley E. The pawl R permitsthe ratchet-teeth to slip under it, one by one, to compensate for thedifference in the speed of rotation of the two axles, and under thesecircumstances no power is transmitted; but the moment any slip of thewheels driven by pulley E occurs the pawl R will transmit power throughthe pulley E" at the same time I endeavor to make the difference betweenthe rates at which the two pulleys or parts of the pulley tend to drivethe car so slight that both pulleys will be practically at all timesdriving, the least slip of the belts or wheels connected with pulley Ebeing sufficient to bring pulley E" into action.

The difference in the diameters of the two pulleys E" and E is so slightas scarcely to be perceptible to the eye, even in the fullsized wheels;hence it is not clearly shown in the drawings, which are made to scale.

In Fig. 12 I have shown a pinion, F, on the motor-shaft meshing with agear, R, mounted on the axle l3, and which takes the place of the pulleyE of Fig. i). The motor is thus geared directly to the axle, and thesprings S S, which take the place of the link I, Figs. 53 and 5, allow acertain movement of the gears bodily about the axle. This movementshould of course be limited.

Ilavin g now described my invention, what I claim is 1. The combination,with the rotary motor of an eleetro-magnetieally-propelled ear or othervehicle, of reducing-gears driven thereby and contained in a casingwhich is carried by the axle of the drivers and secured to the car-bodyto prevent its rotation, as set forth.

2. The combination, with the driving-axle of aneleetro-magnetically-prepelled car or other vehicle, of speed-reducinggears mounted on the axle, a stationary annular gear or toothed ringconcentric with the axle, a box or easing surrounding and inclosing saidlIO gears and secured against rotation, and anelectro-magnetic motorwith motion-transmitting connections between its shaft and the re(lucinggears, as set forth.

3. The combination, with the driving-axle of an electro-magnetieally-propelled car or other vehicle, of 1'G(1U(3ll1g-2,'(5(t1'Smounted upon the axle, a box or casing containing oil and surroundingand inclosing said gears and securedagainstrotation by attachment to thecar-body, and an eleetro-magnetic motor carried. by the ear for drivingsaid gears, as set forth.

in The combination, with the driving-axle of ane]ectro-magnetically-pr0pelled vehicle, of reducing-gears mounted on andsurrounding the axle, a motor, and a belt and pulley for connecting thesame with the gears, a stationary oil box or easing mounted on the axleand inclosing the gears, and a dust-protective casing surrounding thepulley and provided with openings for the belt, as set forth.

5. The combination, with the motor of an ITS electrically-propelledvehicle, of motion-trans mitting pulleys and belts for imparting themotion of the motor-shaft to both axles of the car, one set of saidpulleys and belts being adapted to compensate for differences in thespeed of rotation of the wheels of the respective axles, as herein setforth.

6. A mechanism for imparting the motion of the motor to the axles of anelectricallypropelled vehicle composed of the followinginstrumentalities, combined and adapted for operation in the manner setforth, viz: a motor carried by the car or other vehicle, a double ortwo-part pulley, one part constituting a driving-pulley and capable of alimited movement around the motor-shaft, the other a compensating orequalizing pulley and loosely mounted on the shaft, a double pawlcarried by the driving-pulley which meshes with a ratchet formed on thecompensating pulley, a spring mounted on the motor-shaft and acting toshift the pawl,

. whereby the two pulleys are prevented from moving independent] yineither direction, as may be determined by the action of the spring, andconnections for imparting the motion of the pulleys, respectively, tothe axles of the car.

'7. The combination, with the motor-shaft, of driving and compensatingor equalizing pulleys thereon, geared or connected, respectively, to thetwo axles of the car, the compensating pulley being of smaller diameterthan the driving-pulley to compensate for differences in the sizes ofthe wheels, as set forth.

8. The combination, with the motor-shaft, of the driving-pulley E,having a limited movement around the shaft, the compensating pulley E,loose upon the shaft and formed with the ratchet-teeth Y on the interior of its flange, the double pawl R, pivoted to the pulley E andengaging with the ratchetteeth Y, and the spring Z, secured to themotor=shaft and adapted to engage with and shift the pawl R, as setforth.

9. The combination, with the driving-axles ofelectro-magnetically-propelled cars, of a sleeve, D, and pulley securedthereto, a concentric annular gear, H, secured to the carbody, andintermediate gear-wheels carried by a hub, J, fixed to the shaft andmeshing with the annular gear and suitable teeth upon the sleeve D, asset forth.

10. The combination, with the sleeve D and pulley E, the concentric gearH, and intermediate gears, K, of the heads L M, secured to the annulargear H, and forming a receptacle for containing oil and protecting thereducing-gears, as set forth.

11. The combination, with the reducinggears and the inclosing-casingcontaining oil, of the box or casing M, secured thereto and inclosingthe pulley E.

12. The combination, with the sleeve D, loose upon the axle and providedwith the lubricating-passages m, of the concentric reducing-gears andinclosing oil box or casing, as set forth.

13. The combination, with the axle of a car, of a pulley loose upon saidaxle, an electro-magnetic motor for driving said pulley, and a series ofreducing-gears between the said pulley and the axle, and adapted torotate the axle in the same direction as the pulley, as set forth.

\VILLIAM L. STEVEN S.

Vitnesses:

FRANK G, PARKER, MATTHEW M. BLUNT.

